需要递归地拉动父母创建树r的帮助

Question

我有一个看起来像这样的数据框架：

名字	经理
约翰·	比尔
·比尔	·戴维
·戴维	·莎拉·
莎拉（John Bill David David Sarah

name = c("John","Bill","David","Sarah")
manager = c("Bill","David","Sarah","")
df = data.frame(name,manager)

）（莎拉（Sarah）是梯子的顶级），我只是想做一个简单的查找来吸引约翰的经理（大卫）。 Ideally I would like a recursive loop in R that will run through my dataset and create an output that lists all the managers above each person such as this:

name	manager	output
John	Bill	Bill_David_Sarah
Bill	David	David_Sarah
David	Sarah	Sarah
Sarah

Also please note, my data没有以这种方式订购，经理可以管理多个人，而不是一对一。任何帮助将不胜感激！

Answer 1

这是一个具有igraph的解决方案。从data.frame创建有向图，然后lapply loops提取所需的信息。

name = c("John","Bill","David","Sarah")
manager = c("Bill","David","Sarah","")
df = data.frame(name,manager)

suppressPackageStartupMessages(library(igraph))

g <- graph_from_data_frame(df)
plot(g)

ll <- lapply(V(g), \(v) all_simple_paths(g, from = v, to = V(g)[V(g) != v]))
ll <- lapply(ll, \(l) l[length(l)])
df$output <- sapply(ll[-length(ll)], \(l) {
  if(length(l) > 0) {
    inx <- eval(parse(text = l))[-1]
    nms <- names(ll)[ V(g)[inx] ]
    paste(nms[nms != ""], collapse = "_")
  } else ""
})

df
#>    name manager           output
#> 1  John    Bill Bill_David_Sarah
#> 2  Bill   David      David_Sarah
#> 3 David   Sarah            Sarah
#> 4 Sarah

^{由 reprex软件包（v2.0.1）}